Inactivation of Escherichia coli O157:H7, Salmonella typhimurium and Listeria monocytogenes in apple juice with gaseous ozone

Abstract

This research was initiated to assess the efficacy of gaseous ozone for inactivation Escherichia coli O157:H7, Salmonella typhimurium and Listeria monocytogenes in apple juice. Juice samples with solids content of 18, 36, and 72 degrees Brix inoculated with a culture cocktail of three foodborne pathogens were treated with gaseous ozone at a flow rate of 3.0 L/min and an ozone generation rate of 0.10, 0.90, 3.51, and 5.57 g/h for 0.5, 1, 5, and 10 min, respectively. The inactivation kinetics of gaseous ozone on foodborne pathogens conformed to the Weibull model. The time required to achieve a 5 log reduction (t(5d)) was estimated using the parameters of the Weibull model. The t(5d) increased with increasing solids content of apple juice. The ozone generation rate did not impart a significant effect (p > 0.05) on t(5d). Gaseous ozone is effective at inactivating foodborne pathogens in apple juice but the efficacy is dependent on the solids content of the juice sample. (C) 2012 Elsevier Ltd. All rights reserved.